Direct Voltage MTPA Speed Control of IPMSM-Based Electric Vehicles

A simple maximum torque per ampere (MTPA) method is designed for interior permanent magnet synchronous motors (IPMSMs) with no current control. The proposed method tracks the rotor speed by finding the best pair of voltage angle and amplitude for each motor's speed and torque condition. This is achieved without stand for any current control loop and using a single controller, which makes the technology simple to a great extent, contrary to the majority of methodologies in the literature. Moreover, a thorough insight analysis is provided to determine analytically the control gains, which simplifies control and tuning and makes it a suitable contender for the development of low-cost PMSM drives. To illustrate the capability of the suggested control method, a comparative study is conducted using the popular MTPA vector control strategy. Experimental results for various situations reveal the ability of the suggested MTPA controller in steady-state, standstill, and transient conditions. Additionally, to quantitatively assess the MTPA trajectory tracking accuracy, both control methods are compared using an efficiency metric. Besides, the US06 standard driving cycle is implemented experimentally to validate the proposed method for electric vehicle applications.